Houston was not even a top option for the Big 12. BS on your argument about Okie State. They came within a miracle upset by Iowa State of being in the National Title Game back in 2011. PAC 12 Network has no demand for it. And TCU and Houston do nothing to enhance the Big 12. Go grab Tulane then. Massive Market.
I am not sure what you're not getting here, but the Big 12 doesn't have a conference network, so the fact Houston was 4th in preference to Big 12 isn't a reason why it could not be 2nd for the Pac12. Let alone the fact the Big 12, unlike the Pac12, has an existing presence in Houston. The threat of the Pac12 adding Houston was one of the factors in Houston getting in now.
Your rebuttal is that Ok St's pinnacle moment is getting upset to an average Iowa St team in the middle of a season? Yeah, "we'd be in the title game if not for xyz on a night in November" doesn't resonate in the Pac12 like winning a Rose Bowl.
I have no idea why you type your last two sentences. But the Big 12 has no conference network, so presumably you meant Pac 12 if you're talking market size. And Tulane's marker is not as large as Houston or TCU's, so even then I am not sure how you're making any sense.
Houston and TCU add value to the Big 12 because we need hatred and history matchups, local rivalries, because there are no big brands available, and we do not have a conference network. They also limit the Pac12's options, which is good for when the Pac12 loses teams.